Improvement in chemical telegraphs



T. A. EDISON.

Chemical Telegraphs.

N0. 141,774. PatentedAuguSt12,18.7 3.

UNITED STATES THOMAS A. nnrson, OF'NEWARK, NEW JERSEY, Assreuon TO HIMSELF AND PATENT OFFICE.

GEORGE HARRINGTON, OF WASHINGTON, DISTRICT OF COLUMBIA.

lMPROVEMENT m CHEMICAL TELEGRAPHS.

Specification forming part of Letters Patent N 0. 141,774, dated August 12, 1873 application filed March 13, 1873.

Chemical Telegraphs, of which the following is a specification:

M y invention relates to a chemical telegraph in which the paper is moistened as it runs through the machine, and receives the mark from the electric action upon the chemical ingredients employed." I make use of a trough or pen similar to a paper-ruling pen, and I supply to the same the chemical solution by a siphon, or otherwise, so that the strip of paper is moistened in a line immediately before or at the time that the mark is made, and the electrodes or contact-points are applied to the surface, either contiguous to the place where the liquid solution issues upon the paper, or more or less remote from the same.

Thereby the decomposition of the liquid will be effected just as the same issues from the pen upon the paper, or after the solution has reached the paper and. before it becomes entirely dry. 1

In the drawing, Figure 1 is a plan of the instrument, and Fig. 2 is a side view of the same.

The strip of paper a is drawn along by the rollers b in any of the known modes employed in automatic telegraphy. The solution is ap plied to the surface of the same by arulingpen, such as used by draftsmen, or in paperruling machines;

I have shown the pen 0 as a trough-shape, tapering down to the end that rests upon the paper, and into this trough the chemical solutionis either placed or supplied from a foun tain or reservoir, 0, by a siphon, f, or otherwise.

The wires i Z, that are in the telegraphic circuit, and through which-the electric pulsa-- tions pass, are connected to two points or electrodes, -0 0, that are sufficiently close together toact upon the moist solution and decompose the same and leave the mark upon the paper, and these are placed where they will act upon the solution itself jnst'asit issues'fromthepen upon the paper, or else upon such solution in the paper while it remains in a moist condition, thus insuring the proper mark and employing but a small quantity. of solution.

I am aware that the strip of paper has been moistened in a narrow line by a roller immersed in the chemical solution, so as to apply the same to the paper before coming into position to receive the markybut the paper ofl'ers a great resistance to the current, not being moistened entirely through by the time it reaches the stylus. By employing circuitpoints at the surface at opposite sides of the moistened line this is avoided.

I claim as my invention- The circuit-points or electrodes 0 0, connected with the wires t l and applied at each side of the line of chemical solution upon the surface of the paper,substantially as set forth.

Signedby me this 7th day of March, A. D.. 1873.

THOMAS A. nnrsou.

Witnesses Gno. T PINCiKNEY, CHAS. H. SMITH. 

